PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No more than 2 prior chemotherapy regimens Endocrine therapy: See Disease Characteristics No prior hormonal therapy for metastatic breast cancer No concurrent estrogen (hormone replacement) therapy No other concurrent hormonal agents for breast cancer (e.g., tamoxifen, anastrozole, letrozole, aminoglutethimide, or megestrol) No concurrent corticosteroids for breast cancer unless already receiving such therapy at study entry Radiotherapy: Not specified Surgery: Not specified Other: Concurrent bisphosphonates allowed for bone disease provided measurable disease in non-osseous sites No concurrent anticoagulant therapy